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The Outbreak 

27. J une^!5 Sepl 


The Korean War was the first major armed clash between Free 
World and Communist forces, as the so-called Cold War turned hot. The 
half-century that now separates us from that conflict, however, has 
dimmed our collective memory. Many Korean War veterans have consid- 
ered themselves forgotten, their place in history sandwiched between the 
sheer size of World War II and the fierce controversies of the Vietnam 
War. The recently built Korean War Veterans Memorial on the National 
Mall and the upcoming fiftieth anniversary commemorative events 
should now provide well-deserved recognition. I hope that this series of 
brochures on the campaigns of the Korean War will have a similar effect. 

The Korean War still has much to teach us: about military prepared- 
ness, about global strategy, about combined operations in a military 
alliance facing blatant aggression, and about the courage and persever- 
ance of the individual soldier. The modern world still lives with the con- 
sequences of a divided Korea and with a militarily strong, economically 
weak, and unpredictable North Korea. The Korean War was waged on 
land, on sea, and in the air over and near the Korean peninsula. It lasted 
three years, the first of which was a seesaw struggle for control of the 
peninsula, followed by two years of positional warfare as a backdrop to 
extended cease-fire negotiations. The following essay is one of five 
accessible and readable studies designed to enhance understanding of 
the U.S. Army's role and achievements in the Korean conflict. 

During the next several years the Army will be involved in many 
fiftieth anniversary activities, from public ceremonies and staff rides to 
professional development discussions and formal classroom training. 
The commemoration will be supported by the publication of various 
materials to help educate Americans about the war. These works will 
provide great opportunities to learn about this important period in the 
Army's heritage of service to the nation. 

This brochure was prepared in the U.S. Army Center of Military 
History by William J. Webb. I hope this absorbing account, with its list 
of further readings, will stimulate further study and reflection. A com- 
plete listing of the Center of Military History's available works on the 
Korean War is included in the Center's online catalog: . 

Brigadier General, USA 
Chief of Military History 

The Outbreak 
27June-15 September 1950 

Korea, a small country numbering 30 million people in 1950, lies 
at the point where three great Asian powers meet — Japan, China, and 
the former Soviet Union. Japan ruled Korea from 1910 to 1945. 
Following the defeat of Japan in World War II, the United States and 
the Soviet Union jointly occupied the country, the United States south 
of the 38th Parallel and the Soviet Union north. Preoccupied with 
Soviet intentions in western Europe, the United States attached little 
strategic importance to Korea in the late 1940s. America did assist the 
South Koreans in national elections and in formation of the Republic 
of Korea (ROK). The Soviet Union, on the other hand, took an active 
role in governing North Korea and in formation of the Democratic 
People's Republic of Korea (DPRK). The United States Army with- 
drew its combat forces from South Korea in 1949 but left a military 
advisory group to assist the ROK Army. In early 1950 the Soviets 
supplied weapons to and assigned several thousand Russian soldiers 
as trainers for the North Korean People's Army (NKPA). Armed clash- 
es between North and South Korea were common along the 38th 
Parallel, but in June 1950 American observers did not anticipate an 
invasion of the South. Determined to unite Korea by force, the North 
Koreans invaded South Korea on 25 June. An initially hesitant United 
States decided that it must take a stand against this armed aggression. 
American military intervention was ineffective at first, but by 
September 1950 the combined efforts of the U.S. and ROK Armies, 
complemented by air and naval superiority, held the North Koreans in 
check at the Pusan Perimeter. 

Strategic Setting 

Korea is a mountainous peninsula jutting from the central Asian 
mainland with a shape that resembles the state of Florida. Water out- 
lines most of this small country, which has more than 5,400 miles of 
coastline. The Yalu and Tumen Rivers define much of its northern 
boundary, while major bodies of water are located on its other sides: 
the Sea of Japan on the east, the Korea Strait on the south, and the 
Yellow Sea on the west. China lies above the Yalu and Tumen Rivers 
for 500 miles of Korea's northern boundary as does the former Soviet 
Union for some eleven miles along the lower Tumen River. Korea 
varies between 90 and 200 miles in width and 525 to 600 miles in 

length. High mountains drop down abruptly to deep water on the east 
where there are few harbors, but a heavily indented shoreline on the 
south and west provides many harbors. Summers are hot and humid, 
with a monsoon season that lasts from June to September, but in the 
winter cold winds roar down from the Asian interior. A rugged land- 
scape, a lack of adequate roads and rail lines, and climatic extremes 
make large-scale modern military operations in Korea difficult. In 
1950 the country's population totaled about 30 million: 21 million 
south of the 38th Parallel, with 70 percent of the people engaged in 
agriculture, and 9 million north. 

Japan annexed Korea in 1910 and ruled the country until the end 
of World War II. Unlike the Soviet Union, in 1945 the United States 
attached little strategic importance to Korea. At the Potsdam 
Conference Soviet authorities told American representatives that the 
Soviets would attack Korea after declaring war on Japan, but the col- 
lapse of Japan in August 1945 made a major assault unnecessary. As a 
line to divide Korea into Soviet and American areas for accepting 
Japanese surrender, the U.S. War Department selected the 38th 
Parallel, roughly splitting the country in half. The Soviets agreed to 
operate in the north, and the American forces would operate in the 
south. Also in August 1945 the Joint Chiefs of Staff designated 
General of the Army Douglas MacArthur, as Supreme Commander for 
the Allied Powers, to receive the Japanese surrender. MacArthur 
selected Lt. Gen. John R. Hodge, XXIV Corps commander, to com- 
mand the United States Army Forces in Korea (USAFIK), which 
administered South Korea on behalf of the United States. The foreign 
ministers of the United States, Great Britain, and the Soviet Union met 
in Moscow in December 1945 and developed a plan for a four-power 
trusteeship of Korea for up to five years. Many South Koreans wanted 
their independence immediately and protested violently. The Soviets 
had their own special plans, which involved strong support for the 
Korean Communist Party that assumed political power in the North 
under Kim II Sung. 

In August 1947 the United States, Great Britain, and China agreed 
to reconsider establishment of a four-power trusteeship to facilitate 
Korean unification, but the Soviet Union refused to cooperate. The 
United States then proposed that the United Nations (UN) supervise 
elections in both zones of Korea and that it oversee the formation of a 
national government. Elections took place in South Korea in May 
1948, but the North Koreans neither participated in nor recognized the 
results of the elections. The South Koreans chose representatives for 
the National Assembly of the new Republic of Korea, which then 


elected Syngman Rhee as its chairman. In July 1948 the assembly pro- 
duced a constitution and elected Rhee as president of the republic. 
USAFIK's governmental authority then came to an end. In September 
1948 the North Koreans formed their own government, the 
Democratic People's Republic of Korea under the leadership of Kim II 
Sung, that claimed jurisdiction over all of Korea. The National 
Security Council recommended that all U.S. combat troops leave 
Korea by the end of June 1949, and President Harry S. Truman 
approved the recommendation. 

Attempts to build a native defense force in South Korea began 
shortly after the end of World War II. In January 1946 the Joint Chiefs 
of Staff authorized General MacArthur to form a Korean police force 
and, despite problems with equipment and training, the Korean 
Constabulary grew to 20,000 men by the close of 1947. Washington 
asked MacArthur about the advisability of creating a South Korean 
army. MacArthur proposed instead in February 1948 an increase of the 
Constabulary to 50,000 men. President Rhee asked in November for 
an American military mission, and the Provisional Military Advisory 
Group established by MacArthur in August 1948 was redesignated in 
July 1949 the United States Military Advisory Group to the Republic 
of Korea (KMAG) and authorized 472 soldiers. In November 1948 
South Korea passed the Armed Forces Organization Act, which creat- 
ed a department of national defense. By March 1949 the South had 
converted its Constabulary brigades into an Army of 65,000 men 
assigned to eight tactical divisions — the 1st, 2d, 3d, 5th, 6th, 7th, 8th, 
and Capital Divisions. In June 1950 the ROK armed forces consisted 
of the following: Army, 94,808; Coast Guard, 6,145; Air Force, 1,865; 
and National Police, 48,273. 

In the early summer of 1950 four ROK divisions held positions 
along the 38th Parallel: the 1st, 6th, 7th, and 8th. The 17th Regiment 
of the Capital Division was on the western extreme in the Ongjin 
Peninsula. The other four divisions were scattered about the interior 
and southern parts of the country. The headquarters of the Capital 
Division was located at Seoul, the 2d near Taejon, the 3d at Taegu, and 
the 5th at Kwangju in southwest Korea. When U.S. Armed Forces in 
Korea withdrew from South Korea in 1949, it transferred equipment to 
the ROK Army sufficient for 50,000 men. The weapons of the ROK 
divisions stationed along the 38th Parallel included the American Ml 
rifle, .30-caliber carbine, 60-mm. and 81 -mm. mortars, 2.36-inch rock- 
et launchers, and the M3 105-mm. howitzer. The South Korean armed 
forces had no tanks, no medium artillery, and no fighter aircraft or 
bombers. In October 1949 the ROK minister of defense had requested 


M26 Pershing tanks from the United States, but the KMAG staff con- 
cluded that the rough Korean terrain and inadequate roads would not 
allow efficient tank operations. In June 1950 the ROK Army possessed 
some 2,100 serviceable U.S. Army motor vehicles — 830 272-ton 
trucks and 1,300 74-ton trucks (j ee P s )- The ROK Air Force consisted 
of twelve liaison-type aircraft and ten advance trainers (AT6). The 
ROK Navy had a sprinkling of small vessels that included patrol craft 
along with mine layers and sweepers. 

The North Korean People's Army was officially activated in 
February 1948. The Soviets exercised close control over its organization 
and training, and Soviet advisers worked directly with units. At that time 
150 Soviets were assigned to each division; the number dropped to 20 
per division in 1949 and to a lesser number by 1950 as trusted North 
Korean officers were developed. By June 1950 the NKPA and the Border 
Constabulary numbered about 135,000. The primary tactical units con- 
sisted of eight full-strength infantry divisions of 11,000 men each, two 
more infantry divisions at half strength, a separate infantry regiment, a 
motorcycle-reconnaissance regiment, and an armored brigade. The 
NKPA benefited from some 20,000 North Koreans who were veterans of 
the Chinese civil war of the late 1940s, which gave its units a combat- 
hardened quality and efficiency. The Soviet Union supplied much of the 
materiel for the NKPA. Of primary importance was the T34 medium 
tank, a mainstay of the Soviet armored force in World War II that 
weighed 32 tons and mounted an 85-mm. gun. The Soviets also supplied 
artillery support that resembled the weaponry of the older Soviet divi- 
sion of World War II: 76-mm. and 122-mm. howitzers, 45-mm. antitank 
guns, and 82-mm. and 120-mm. mortars. At the outset of the war North 
Korea had about 180 Soviet aircraft— 60 YAK trainers, 40 YAK fight- 
ers, 70 attack bombers, and 10 reconnaissance planes. Like the ROK 
Navy, the North Korean naval forces had only a few small vessels — six- 
teen patrol craft and several coastal steamers. 

U.S. strategic planning after World War II centered on the Soviet 
Union and its satellite nations. In 1950, as the single most powerful 
nation in the North Atlantic Treaty Organization, America gave first 
claim for its military resources to the defense of western Europe. Not 
only did the United States give priority to Europe over the Pacific and 
Far East, in April 1948 President Truman had approved a policy that 
no problems within Korea could become a casus belli for the United 
States. In January 1950, in a speech to the National Press Club in 
Washington, D.C., Secretary of State Dean G. Acheson announced an 
American defensive strategy in the Far East that excluded both Korea 
and Formosa. 


The Joint Chiefs of Staff had designated General MacArthur as 
Commander in Chief, Far East Command (FEC), effective January 
1947. The boundaries of FEC were not specific, but MacArthur com- 
manded forces in Japan, Korea, the Philippines, and other island 
groups. He was responsible for the American occupation of and for 
general emergencies in those areas. Along with United States Army 
Forces, Far East, MacArthur also controlled Far East Air Forces and 
Naval Forces, Far East. 

In June 1950 the active United States Army had an authorized 
strength of 630,201 with an actual strength of about 591,000 and ten 
combat divisions. Some 360,000 troops were at home, while the 
remaining 231,000 were in overseas commands with 80,000 in 
Germany and 108,500 in the Far East. The force designated to handle 
the Army's emergency assignments was the General Reserve, which 
consisted mainly of five combat divisions stationed in the United 
States: 2d Armored Division, 2d and 3d Infantry Divisions, and the 
11th and 82d Airborne Divisions. The Far East Command had four 
tactical divisions and a regimental combat team (RCT) — the 1st 
Cavalry Division, the 7th, 24th, and 25th Infantry Divisions, and the 
29th RCT — that operated under the command of the Eighth U.S. Army 
in Japan. Each division was short of its authorized war strength of 
18,900 by nearly 7,000 men and had major shortages in artillery bat- 
teries and equipment. The FEC had received no new vehicles, tanks, or 
other equipment since World War II. Army personnel stationed in 
Japan had performed primarily occupation duties, and no serious 
effort had been made to attain combat efficiency at battalion level or 
higher. Convinced that a purely occupational mission was no longer 
needed, MacArthur issued a policy directive in April 1949 that called 
for an intensified training program for ground, naval, and air units in 
FEC. By May 1950 Eighth Army's divisions had reportedly reached 
combat readiness levels that ranged from 65 to 84 percent. 

As early as 1947 the North Korean Communists employed propa- 
ganda and even armed violence to instigate the overthrow of the South 
Korean government. On 3 May 1949, the North Koreans launched 
their first open attack across the 38th Parallel in the vicinity of 
Kaesong, but ROK units repulsed them. Hundreds of small-scale 
assaults occurred across the parallel during the first half of 1950; how- 
ever, some encounters inflicted heavy casualties on both sides. A 
series of guerrilla uprisings on the island of Cheju-do spread to the 
mainland by late 1948, but by June 1950 the ROK Army had virtually 
eliminated them, claiming to have killed about 5,000 insurgents. By 
late 1949 talk of a North Korean invasion was almost routine in intelli- 


gence circles, but it went unnoticed against the background of threat- 
ening Communist activities in other parts of the world — Southeast 
Asia, western Europe, and the Middle East. In the early summer of 
1950 senior American observers discounted the likelihood of a North 
Korean invasion. Both Maj. Gen. Charles A. Willoughby, the FEC 
G-2 (intelligence officer), and the American embassy in Seoul opined 
that an attack was unlikely and that the North Koreans would continue 
to employ guerrillas and psychological warfare. The officers of the 
KMAG felt that an attack by North Korea was not imminent and, if it 
happened, they thought that the South Koreans could repel it. Since 
the United States had no plan to counter an invasion, any debate about 
an American intelligence failure regarding the North Korean attack 
was academic. 


During 15-24 June 1950, the North Korean High Command 
assembled some 90,000 men — 7 infantry divisions, 1 armored brigade, 
1 separate infantry regiment, 1 motorcycle regiment, and 1 Border 
Constabulary brigade — supported by 150 Soviet T34 tanks near the 
38th Parallel. At 0400 on 25 June the North Koreans launched a coor- 
dinated attack on South Korea that ran from coast to coast. The assault 
began on the Ongjin Peninsula on the western extreme of the parallel, 
but the North Koreans concentrated half of their forces on the 
Uijongbu Corridor, an ancient invasion route that led directly south to 
Seoul. The ROK 1st, 2d, 7th, and Capital Divisions defended the area 
north of Seoul, but the suddenness of the North Korean attack and the 
shock of enemy armor rapidly pushed the ROK Army back toward 
Seoul. In the early hours of 28 June the South Korean vice minister of 
defense ordered a premature blowing of the Han River bridges, located 
on the southern edges of Seoul, to slow the North Korean advance. 
This was catastrophic for the ROK Army. Much of the Army was still 
north of the river and had to abandon transport, supplies, and heavy 
weapons and cross the Han River in disorganized groups. The ROK 
Army numbering 95,000 on 25 June could account for only 22,000 
men at the end of June. 

The UN Security Council met on 25 June and passed a resolution 
that called on North Korea to cease hostilities and withdraw to the 
38th Parallel. President Truman authorized ships and airplanes to pro- 
tect the evacuation of American dependents in Korea and also use of 
American air and naval forces to support the Republic of Korea below 
the 38th Parallel. On 27 June the UN Security Council passed another 


resolution that recommended UN members assist South Korea in 
repelling the invasion. The Joint Chiefs of Staff issued a directive that 
authorized MacArthur to assume operational control of all American 
military activities in Korea. MacArthur then sent the General 
Headquarters Advance Command and Liaison Group in Korea 


General MacArthur discusses the military situation with 
Ambassador John J. Muccio at ROKArmy headquarters, 29 June 1950. 
(National Archives) 

(ADCOM), headed by Brig. Gen. John H. Church, from Japan to 
South Korea to administer KMAG and assist the ROK Army. On 29 
June MacArthur personally inspected the situation at the Han River 
and urged the immediate commitment of American ground forces. 
President Truman then authorized the employment of Army combat 
troops to ensure a port and air base at Pusan, South Korea, and more 
importantly, approved sending two Army divisions from Japan to 
Korea and the establishment of a naval blockade of North Korea. 

Following the breakdown of the ROK Army at Seoul, elements of 
the North Korean 3d and 4th Divisions captured the South Korean cap- 
ital on 28 June. The North Koreans then repaired a railroad bridge 
over the Han River, and by 4 July these two divisions, with T34 tank 
support, were poised to resume their drive south. In Tokyo on 30 June 
General MacArthur instructed Lt. Gen. Walton H. Walker, Eighth U.S. 
Army commander, to order the 24th Infantry Division, stationed on 
Kyushu, to Korea at once. Maj. Gen. William F. Dean, commander of 
the 24th, was to send immediately to Korea by air a delaying force of 
about 500 men, and the rest of the division would soon follow by 


water. General Dean would assume command of USAFIK, reinstated 
as a provisional headquarters, upon his arrival. Lt. Col. Charles B. 
Smith, commander of the 1st Battalion, 21st Infantry, of the 24th 
Division, led the delaying force, called Task Force Smith. On 5 July he 
established a defensive position three miles north of Osan, assisted by 
elements of the 52d Field Artillery Battalion. Task Force Smith took 
on two regiments of the North Korean 4th Division and thirty-three 
T34 tanks. Badly outnumbered and without armor, effective antitank 
weapons, or air support, the U.S. force was overrun. The next day, 
Colonel Smith could assemble only 250 men, half his original force. 

On 4 July General Dean assumed command of USAFIK and 
established his headquarters at Taejon. The 34th Infantry, another 
organic regiment of Dean's 24th Division, and the rest of the 21st 
Infantry arrived in Korea during the first week of July. During that 
week General MacArthur ordered General Walker to deploy from 
Japan and assume operational control of the campaign in Korea. 
Walker set up his headquarters for the Eighth U.S. Army in Korea at 
Taegu and on 13 July assumed command of USAFIK. Shortly there- 
after, he also took command of ROK ground forces. Walker's objec- 
tives were to delay the enemy advance, secure the current defensive 
line, and build up units and materiel for future offensive operations. 
On 7 July the UN Security Council passed a resolution that recom- 
mended a unified command in Korea. President Truman then appoint- 
ed MacArthur commanding general of the military forces under the 
unified command that became the United Nations Command. 
MacArthur's strategy in the early stages of the Korean War was first to 
stop the North Koreans and then use naval and air superiority to sup- 
port an amphibious operation in their rear. Once he realized that the 
North Korean People 's Army was a formidable force, MacArthur esti- 
mated to the Joint Chiefs of Staff that to halt and hurl back the North 
Koreans would require four to four-and-a-half full-strength infantry 
divisions, an airborne regimental combat team, and an armored group 
of three medium tank battalions and reinforcing artillery. 

After the defeat of Task Force Smith, General Dean employed the 
34th and 21st Infantries in additional delaying actions against the 
advance of the North Korean 3d and 4th Divisions along the corridor 
that ran south of Osan toward Taejon. Fighting occurred at 
P'yongt'aek, Ch'onan, Chonui, and Choch'iwon. Dean sought to delay 
the enemy's approach to the Kum River to support the ROK forces' 
left flank that was retreating through the central mountains of South 
Korea. By early July the ROK Army, which became badly disorga- 
nized after the fall of Seoul, had re-formed to some extent. From west 


to east, the ROK Army line was held by the 17th Regiment; the 2d, 
Capital, 6th, and 8th Divisions; and the 23d Regiment of the 3d 
Division. The major part of the NKPA conducted a main attack on a 
wide front against ROK-defended territory, which was everything east 
of the main Seoul-Taegu railroad and highway. Five divisions moved 
south over the two mountain corridors, while a sixth, the 2d Division, 
followed the road from Ch'ongju through Poun to Hwanggan where it 
entered the Seoul-Taegu highway. The North Korean 1st, 13th, and 
15th Divisions moved over one mountain corridor and across the 
Mun'gyong plateau, while the 8th and 12th Divisions came down the 
eastern corridor. On the east coast along the Sea of Japan, the North 
Korean 5th Division and the 766th Independent Infantry Regiment 
marched south and met virtually no opposition. The trackless moun- 
tains of the Taebaek Range effectively separated the east coast of 
Korea below the 38th Parallel from the rest of the country. 

In mid- July 1950 General Dean's 24th Division continued as the 
primary U.S. Army fighting force in Korea. Taejon, located 100 miles 
south of Seoul, served as an important road and communications cen- 
ter. The Kum River makes a semicircle to the north around Taejon that 
constitutes a protective moat. Dean placed his 24th Division in a 
horseshoe-shaped arc in front of Taejon — the 34th Infantry on the left, 
the 19th Infantry on the right, and the 21st Infantry in reserve. By 
positioning elements of the 34th at Kongju, located about twenty miles 
northwest of Taejon, Dean hoped to prevent the North Koreans from 
an early crossing of the Kum River and an immediate drive on Taejon. 
Since the division had only about 4,000 men at Taejon, the 24th could 
not effectively delay two enemy divisions. During 14-16 July the 
North Korean 4th and 3d Divisions, operating west to east, penetrated 
the 34th and 19th Infantries' forward defensive positions on the south 
side of the Kum River and inflicted substantial casualties. Dean then 
pulled his regiments into a tighter defensive perimeter around Taejon, 
and the North Koreans launched their attack on Taejon on 19 July. The 
men of the 24th at Taejon enjoyed one positive development. They had 
just received a weapon that was effective against the T34 tank, the new 
3.5-inch rocket launcher. The five-foot hand-carried launcher fired a 
two-foot-long eight-and-a-half-pound rocket with a shaped charge 
designed to burn through any tank then known. U.S. Army soldiers 
destroyed ten enemy tanks in Taejon on 20 July, eight of them with the 
3.5-inch rocket launcher. 

The superior numbers and relentless assault of the North Koreans 
forced the men of the 24th Division to abandon Taejon on 20 July and 
withdraw to the south. General Dean experienced one of the most dra- 


General Walker (left) is greeted on arrival at Taejon by General Dean. 
(National Archives) 

matic adventures of the withdrawal. Moving down the road to 
Kumsan, Dean and a small party encountered an enemy roadblock. 
Forced back, Dean's party, with some wounded, set out on foot after 
dark. While trying to fetch water for the injured, Dean fell down a 
steep slope, was knocked unconscious, and suffered a gashed head and 
a broken shoulder. Separated from his men, Dean wandered alone in 
the mountains for thirty-six days trying to reach the American lines 
and was betrayed by two South Koreans to the North Koreans. He 
would spend the next three years as a prisoner of war. Dean was 
awarded the first Medal of Honor for service in the Korean War for his 
leadership and personal bravery with the 24th Division at Taejon. The 
division suffered a 30 percent casualty rate there and lost all of its 
organic equipment. The unit had endured many deficiencies since its 
arrival in Korea. Among them were new subordinate unit commanders 
who were unfamiliar with their men, poor communications equipment, 
a shortage of ammunition, outdated maps, and large numbers of young 
soldiers in the ranks who were inadequately trained for combat. As for 
the North Koreans, in five days they had executed two highly success- 
ful envelopments of American positions, one at the Kum River and the 


A 3. 5 -inch rocket launcher on a battlefield, 20 July 1950 
(National Archives) 

other at Taejon. Each time, they combined strong frontal attacks with 
movements around the left flank to establish roadblocks and obstruct 
the escape routes. 

The 24th Division would soon share the defense of South Korea 
with the rebuilt ROK Army and two newly arrived U.S. Army divi- 
sions, the 25th Infantry Division and the 1st Cavalry Division. On 24 
July the ROK Army reorganized itself into two corps and five divi- 
sions. The ROK I Corps controlled the 8th and Capital Divisions, 
while the ROK II Corps controlled the 1st and 6th Divisions. A 
reconstituted ROK 3d Division was placed under direct ROK Army 
control. The ROK II Corps headquarters was at Hamch'ang with its 
1st and 6th Divisions on line from west to east, and the I Corps head- 
quarters was at Sangju with the 8th and Capital Divisions on line 
from west to east. The 3d Division operated on the east coast of South 
Korea. Large numbers of recruits and replacements had entered the 
ROK Army, which had regained its prewar strength of about 95,000. 
The U.S. 25th Division, with its three regiments — 24th, 27th, and 
35th — commanded by Maj. Gen. William B. Kean, arrived during 
10-15 July 1950 at Pusan. General Walker ordered the 25th to bolster 
ROK defenses of the central mountain corridors. The 1st Cavalry 
Division, with its three regiments — 5th, 7th, and 8th — sailed from 


Japan and landed at P'ohang-dong north of Pusan during 15-22 July. 
The unit assumed responsibility for blocking the enemy along the 
main Taejon-Taegu corridor. In late July both the 25th Division and 
the 1st Cavalry Division withdrew steadily in the face of aggressive 
North Korean attacks. On 29 July General Walker, with the support of 
General MacArthur, issued what the press called a "stand or die" 
order to the Eighth Army. Walker emphasized that the retreating must 
stop. The Eighth Army had been trading space for time and was run- 
ning out of space. 

One of the major problems of the retreat was the volume of 
refugees moving through Eighth Army lines. Their numbers were 
greater during July and August 1950 than at any other time in the war. 
During the middle two weeks of July about 380,000 refugees crossed 
into ROK-held territory. The North Koreans often exploited the situa- 
tion by launching attacks that began with herding groups of refugees 
across minefields and then following up with tanks and infantry. The 
enemy also infiltrated U.S. Army lines by wearing the traditional white 
civilian clothing and joining groups of refugees, thus enabling him to 
commit a variety of surprise attacks on American soldiers. The com- 
manders of the 25th Infantry and 1st Cavalry Divisions attempted 
unsuccessfully to control the volume of refugees and enemy infiltra- 
tion by searching displaced civilians and limiting the times and routes 
available for their movements. In late July General Walker, with the 
cooperation of ROK authorities, set explicit rules for the organized 
removal of refugees to the rear by the ROK National Police. By the 
end of July the ROK government had established fifty-eight refugee 
camps, most of them in the Taegu-Pusan area, to care for the home- 
less. But even with these efforts, refugees continued to hamper the 
movement of U.S. and ROK troops throughout the battlefield. 

As the Eighth Army neared a natural defensive position along the 
Naktong River, the North Koreans accelerated their efforts to cut off 
elements of that army. After the fall of Seoul in late June the North 
Korean 6th Division had crossed the Han River and rapidly moved 
south over the western coastal roadnet. Eighth Army intelligence lost 
track of the 6th. The only UN forces situated at the time southwest of 
the Taejon-Taegu-Pusan highway were a few hundred ROK 7th 
Division survivors along with some scattered ROK marines and local 
police. On 21 July General Walker learned that a North Korean unit, 
presumed to be the 4th Division, was operating in the southwest area. 
Walker ordered the 24th Division, despite its deficiencies in manpower 
and equipment after the loss of Taejon, to serve as a blocking force in 
the area from Chinju in deep south central Korea northward to 


Kumch'on. Two battalions of the 29th Infantry, then stationed on 
Okinawa, and the ROK 17th Regiment would reinforce the 24th 
Division. On 23 July the North Korean 4th Division moved south from 
Taejon with the intent of supporting the 6th Division in an envelop- 
ment of the United Nations' left flank and driving to Pusan. The 4th 
pushed as far as the Anui-Koch'ang area, about fifty miles southwest 
of Taegu, by the end of July. During 25-28 July the two battalions of 
the 29th were driven back by elements of the 6th at Hadong, located 
about twenty-five miles west of Chinju. On 31 July the Eighth Army 
finally became aware of the 6th Division's presence after the 6th took 
Chinju and forced one battalion of the 29th and the 19th Infantry of 
the 24th Division to withdraw to the east. Eighth Army rushed the 
27th Infantry of the 25th Division, which had been in reserve, to rein- 
force American units in the Chinju-Masan corridor. The 24th and 25th 
Divisions, aided by the ROK 17th Regiment, finally managed to slow 
the progress of the North Korean 4th and 6th Divisions at what would 
become the southernmost sector of the Pusan Perimeter. By 3 August 
U.S. and ROK units had averted the immediate threat of a North 
Korean drive all the way to Pusan. 

On 1 August the Eighth Army issued an operational directive to 
all UN ground forces in Korea for their planned withdrawal east of the 
Naktong River. UN units would then establish main defensive posi- 
tions behind what was to be called the Pusan Perimeter. The intent was 
to draw the line on retreating and hold off the NKPA while the U.S. 
Army could build up its forces and wage a counteroffensive. The 
Pusan Perimeter assumed by U.S. and ROK forces on 4 August 
involved a rectangular area about 100 miles from north to south and 
50 miles from east to west. The Naktong River formed the western 
boundary except for the southernmost 15 miles where the Naktong 
turned eastward after its confluence with the Nam River. The ocean 
formed the eastern and southern boundaries, while the northern 
boundary was an irregular line that ran through the mountains from 
above Waegwan to Yongdok. From the southwest to the northeast the 
UN line was held by the U.S. 25th and 24th Infantry and 1st Cavalry 
Divisions, and then by the ROK 1st, 6th, 8th, Capital, and 3d 
Divisions. From south to northeast the North Korean units positioned 
opposite the UN units were the 83 d Motorized Regiment of the 105th 
Armored Division and then the 6th, 4th, 3d, 2d, 15th, 1st, 13th, 8th, 
12th, and 5th Divisions and the 766th Independent Infantry Regiment. 
The 5th Regimental Combat Team from Hawaii and the phased arrival 
of the 2d Infantry Division from the United States augmented U.S. 
Army forces. A third major reinforcement arrived in Korea on 2 


August, the 1st Provisional Marine Brigade, about 4,700 men. UN 
combat forces at this point actually outnumbered the North Koreans, 
92,000 to 70,000. 

The North Koreans had four possible avenues of advance leading 
to Pusan that could result in the defeat of U.S. and ROK forces, and in 
August they tried them all simultaneously. These approaches went 
through Masan south of the confluence of the Nam and Naktong 
Rivers, through the Naktong Bulge to the rail and road lines at 
Miryang, through Kyongju and down the east coast corridor, and 
through Taegu. During the first week of August General Walker decid- 
ed to launch the first American counterattack of the war in the Chinju- 
Masan corridor. One of his purposes was to break up a suspected 
massing of enemy troops near the Taegu area by forcing the diversion 
of some North Korean units southward. On 6 August the Eighth Army 
issued the operational directive for the attack by Task Force Kean, 
named for the 25th Division commander. Task Force Kean consisted 
of the 25th Division, less the 27th Infantry and a field artillery battal- 
ion, with the 5th RCT and the 1st Provisional Marine Brigade 
attached. The Army plan of attack required the force to move west 
from positions then held near Masan, seize the Chinju Pass, and secure 
the line as far as the Nam River. Task Force Kean launched its strike 
on 7 August but ran head-on into one being delivered simultaneously 
by the North Korean 6th Division. After a week of heavy fighting, nei- 
ther Kean's troops nor their opponents had made any appreciable 
progress. Even so, the Eighth Army had launched its first offensive in 
Korea and successfully halted an assault by an enemy division. 

Seven air miles north of the point where the Naktong River turns 
east and the Nam River enters it, the Naktong curves westward oppo- 
site Yongsan in a wide semicircular loop. This loop became known to 
the American troops as the Naktong Bulge during the bitter fighting 
there in August and September. On 6 August the North Korean 4th 
Division crossed the Naktong at Ohang with the intent of driving to 
Yongsan located about ten miles to the east. The 24th Division defend- 
ed that sector and the 24th commander, Maj. Gen. John H. Church, 
who had succeeded General Dean as division commander, placed the 
defense of the Naktong Bulge under Task Force Hill. Task Force Hill 
consisted of the 9th Infantry of the 2d Infantry Division along with the 
34th and 19th Infantries and a battalion of the 21st Infantry of the 24th 
Division. Despite the efforts of Task Force Hill, by 1 1 August the 4th 
Division had penetrated to the vicinity of Yongsan. General Walker 
then added to the fray the 23d Infantry of the 2d Division, the 27th 
Infantry of the 25th Division, and the 1st Provisional Marine Brigade. 


Two American soldiers with a North Korean prisoner of war, 
5 August 1950 (National Archives) 

General Church led the coordinated attack of Army and Marine Corps 
troops against the North Koreans that began on 17 August. By the 
eighteenth the American forces had decisively defeated the 4th 
Division, which had lost half its original strength of about 7,000 men. 

Located about twenty miles south of P'ohang-dong on the east 
coast, Kyongju was an important rail and highway center situated 


within the Taegu-P'ohang-dong-Pusan triangle inside the Pusan 
Perimeter. The capture of P'ohang-dong and the nearby Yonil Airfield, 
used by the Far East Air Force, would open a natural and essentially 
undefended corridor for the NKPA to move directly south through 
Kyongju to Pusan. General Walker had only lightly fortified the east 
coast corridor because the enemy threat was more immediate on the 
western perimeter, and he doubted that the North Koreans could 
mount a major successful drive through the trackless mountains. In 
early August the enemy almost proved Walker wrong when three 
North Korean divisions — the 5th, 8th, and 12th — and the 766th 
Independent Infantry Regiment mounted strong attacks against the 
ROK defenders. By 12 August the North Koreans had pressed to 
P'ohang-dong and also threatened Yonil Airfield. The North Korean 
5th Division cut off the ROK 3d Division above P'ohang-dong, and 
the 3d Division had to be evacuated by sea to positions farther south. 
General Walker reinforced the ROK units in the area with elements of 
the U.S. 2d Infantry Division. By 17 August ROK units and the 2d 
Division had managed to check the enemy drive at P'ohang-dong. A 
primary factor in stopping the North Koreans was logistics, as the 
enemy had outrun his supply line during the difficult trek southward 
through the mountains. 

The natural corridor of the Naktong Valley from Sangju to Taegu 
presented another principal axis of attack for the NKPA. The sizable 
enemy forces assembled in an arc around Taegu in early August from 
south to north consisted of the 10th, 3d, 15th, 13th, and 1st Divisions 
and elements of the 105th Armored Division. Opposite the North 
Korean divisions were the U.S. 1st Cavalry Division and the 1st and 6th 
Divisions of the ROK II Corps. The North Koreans crossed the 
Naktong River in several places within the arc around Taegu during the 
second week of August. When several enemy artillery shells landed in 
Taegu on 18 August, President Rhee ordered movement of the Korean 
provincial government, then in Taegu, to Pusan. The North Korean 1st 
and 13th Divisions posed the primary threat as they pressed toward 
Taegu by overland routes from the north and northwest. General Walker 
moved up the 23d and 27th Infantries, both fresh from defensive action 
in the Naktong Bulge, to reinforce the ROK 1st Division, which con- 
fronted the North Korean 1st and 3d Divisions in its sector. Although 
the North Korean 1st Division pushed to within nine miles of Taegu, 
the combined efforts of the ROK 1st Division and the U.S. 23d and 
27th Infantries frustrated enemy efforts to penetrate to Taegu. 

Even though the North Korean People 's Army had seriously threat- 
ened the United States and ROK Armies within the Pusan Perimeter 


during August 1950, the defenders both successfully resisted the 
enemy attacks and continued the buildup of forces for a counteroffen- 
sive. The Far East Air Force had established air supremacy over the 
North Koreans early in the war and continued to influence the outcome 
of battles by multiple sorties in close support of ground troops, 4,635 
in July and 7,397 in August. By late August there were more than 500 
American medium tanks within the Pusan Perimeter. The tanks in tank 
battalions were equally divided between M26 Pershings and M4A3 
Shermans, except for one battalion that had the newer M46 Pattons. 
On 1 September the United Nations Command had a strength of 
180,000 in Korea: 92,000 were South Koreans and the balance were 
Americans and the 1,600-man British 27th Infantry Brigade. In 
August the North Koreans continued the plan and tactics begun at the 
Han River in early July with a frontal holding attack, envelopment of 
the flank, and infiltration to the rear. When the Eighth Army stabilized 
the line at the Pusan Perimeter, these tactics no longer worked and suc- 
cess could come only by frontal attack, penetration, and immediate 
exploitation. Generals Mac Arthur and Walker countered with classical 
principles of defense — interior lines of communications, superior 
artillery firepower, and a strong air force. By 1 September the North 
Koreans had assembled a 98,000-man army for a massive offensive 
against the Pusan Perimeter. However, they experienced substantial 
problems: a third of their ranks manned by forcibly conscripted and 
untrained South Koreans, a major shortage of small arms, and only 
enough rations for one or sometimes two meals a day. 

In early September as during August, General Walker faced dan- 
gerous situations in essentially the same places along the Pusan 
Perimeter: in the east at P'ohang-dong to include a potential severing 
of the corridor between Taegu and P'ohang-dong, north of Taegu 
where the enemy made disturbing gains, at the Naktong Bulge, and in 
the Masan area in the extreme south. Also as he had during the fight- 
ing in August, Walker continued his masterful tactics of shifting his 
forces from one threatened enemy penetration to another. In early 
September the ROK 3d, Capital, 8th, and 6th Divisions held the line 
farthest to the east against the North Korean 5th, 8th, 12th, and 15th 
Divisions. Maj. Gen. John B. Coulter, newly appointed deputy com- 
mander, Eighth Army, assumed command of American units in the 
eastern sector and employed the 21st Infantry of the U.S. 24th 
Division and other supporting units to bolster the ROK divisions. On 7 
September General Church replaced Coulter as American commander 
in the eastern sector after General Walker ordered the entire 24th to 
reinforce the ROK divisions. A combination of ground fighting, pre- 


dominantly by the South Koreans, along with American close air sup- 
port and naval gunfire from offshore inflicted serious losses on the 
enemy divisions. The North Korean 1st, 3d, and 13th Divisions 
pressed the attack north of Taegu against the U.S. 1st Cavalry 
Division, which prompted Walker on 5 September to move the main 
Eighth Army headquarters from Taegu to Pusan. The 1st Cavalry 
Division essentially checked the thrusts of the North Koreans north of 
Taegu, but fighting continued there into mid-September. 

At the end of August the North Korean People's Army also 
planned a crushing blow against the U.S. 2d and 25th Divisions in the 
southern part of the Pusan Perimeter. The enemy's 6th Division would 
attack through Haman, Masan, and capture Kumhae, fifteen miles west 
of Pusan. The 7th Division was to strike north of the Masan highway, 
wheel left to the Naktong River, and wait for the 6th Division on its 
right and the 9th on its left and then resume the attack toward Pusan. 
The 25th Division held the southernmost sector that ran from the con- 
fluence of the Naktong and Nam Rivers to the southern coast, while 
the 2d Division was positioned in the area across the Naktong River 
north of the 25th. The North Korean 9th Division faced the 2d 
Division at the Naktong Bulge and had the mission of capturing the 
towns of Miryang and Samnangjin, thereby cutting off the Eighth 
Army route of withdrawal between Taegu and Pusan. During the first 
week of September the 9th Division penetrated the Naktong Bulge as 
far east as Yongsan, but a counterattack by the 2d Division together 
with the U.S. 1st Provisional Marine Brigade pushed back the 9th 
almost to the Naktong River. The 2d Division's 23d Infantry beat back 
the North Korean 2d Division six miles north of Yongsan at 
Changnyong. At the same time the 6th and 7th Divisions mounted 
strong attacks against the 25th Division. Despite enemy penetrations 
into the sectors of the 25th 's regiments — the 35th Infantry's sector 
west of Ch'irwon and the 24th Infantry's sector near Haman that was 
effectively stopped by the 27th Infantry — the 25th Division repelled 
the NKPA's offensive in the south. The Naktong River line held, and 
the Pusan Perimeter was secure. 


Within the space of a few months in 1950, the United States had 
taken the big leap from attaching no strategic importance to Korea to 
active involvement there in a major armed conflict. Its active Army of 
591,000 had been focused on Soviet intentions in western Europe and 
occupation duty in Europe and the Far East. The four divisions under 


MacArthur's Far East Command 
in Japan were performing primar- 
ily occupation duties, and their 
actual readiness level for conven- 
tional combat was even lower 
than their marginal statistical rat- 
ings indicated. Each of 
MacArthur's divisions was about 
7,000 men short of its authorized 
strength of 18,900, and none of 
them had received any new 
equipment since World War II. 
MacArthur had not fully support- 
ed development of the ROK 
Army, and in 1948 he had sug- 
gested merely expanding the 
ROK Constabulary. When the 
ROK minister of defense in 1949 
requested M26 Pershing tanks 
from America, the KMAG argued 
that the Korean terrain and roads 
would not allow tank operations, 
a clearly inaccurate prediction of 
the Soviet T34 tank's performance in South Korea during the war's 
early stages. When USAFIK withdrew from South Korea in 1949, it 
did transfer to the ROK Army individual weapons and equipment suf- 
ficient for 50,000 men, but these small arms were incapable of 
repelling enemy armored attacks. 

America failed to anticipate the North Korean invasion, and 
KMAG erred in concluding that the ROK Army could withstand an 
invasion if it happened. Nevertheless, when the attack came the United 
States decided to intervene on behalf of South Korea. President 
Truman authorized air and naval support early in the conflict and the 
progressive introduction of ground troops. The defeat of Task Force 
Smith underscored the importance of adequate prewar training along 
with armored and air support in combat operations. Further, 
MacArthur underestimated the skill and determination of the North 
Koreans but recognized his error when he concluded that more than 
four U.S. divisions were needed to defeat the enemy. The combined 
efforts of the U.S. and ROK Armies led by General Walker, comple- 
mented by air and naval superiority, slowed the southward drive of the 
North Koreans and ended in a difficult but successful defense of the 

Medics evacuate wounded of the 
5th Regimental Combat Team hit 
near Masan, 30 August 1950. 
(National Archives) 


Pusan Perimeter. The fighting was intense as reflected in American 
casualties to mid-September 1950—4,599 battle deaths, 12,058 
wounded, 401 reported captured, and 2,107 reported missing in action. 
The bitter weeks of retreat and death would soon change, however, 
with MacArthur's "hammer against the anvil": the breakout from the 
Pusan Perimeter coupled with the landing at Inch' on by the 1st Marine 
Division and the Army's 7th Infantry Division during the third week of 


Further Readings 

Appleman, Roy E. South to the Naktong, North to the Yalu. United 
States Army in the Korean War. Washington, D.C.: U.S. Army 
Center of Military History, 1961. 

Blair, Clay. The Forgotten War: America in Korea. New York: Time 
Books, 1988. 

Collins, J. Lawton. War in Peacetime: The History and Lessons of 

Korea. Boston: Houghton Mifflin, 1969. 
Dean, Major General William F. General Dean's Story. New York: 

Viking Press, 1954. 
Edwards, Paul M. The Pusan Perimeter, Korea, 1950: An Annotated 

Bibliography. Westport, Conn.: Greenwood Press, 1994. 
Ridgway, Matthew B. The Korean War. Garden City, N.Y: Doubleday, 


Schnabel, James F. Policy and Direction: The First Year. United States 
Army in the Korean War. Washington, D.C.: U.S. Army Center of 
Military History, 1972. 


CMHPub 19-6 

Cover: Troops of the 1st Cavalry Division in action against 
North Korean invaders, 25 July 1950. 

PIN : 077983-000